1. Field of the Invention
The present invention relates to a suspension strut of the type including a cylinder; a chamber surrounding the cylinder, the chamber being at least partially filled with hardenable material; and a spring collar having a sleeve section which is received in the hardenable material so that said material, in a solid state, transmits a supporting force from the cylinder to the spring collar.
2. Description of the Related Art
A suspension strut unit with a detachable spring collar is disclosed in DE 85 10 058 U1, wherein the spring collar is supported by a retaining ring. The retaining ring in turn can be attached independently of the spring collar to the cylinder of the suspension strut unit, whereupon the overall structural unit thus formed is painted. The height of the spring collar is determined by the retaining ring and cannot be changed.
DE 198 51 019 C1 discloses a suspension strut unit with a cylinder which carries a retaining ring for a spring collar, which can be adjusted and held in place permanently in the desired position. At least one groove is formed in the retaining ring, and at least one circumferential area of a sleeve section of the spring collar can be deformed in the radial direction so that it engages in this groove. The distance by which the groove extends along the sleeve section determines the maximum degree to which the height of the spring collar can be adjusted.
DE 197 44 757 A1, furthermore, describes a spring assembly for motor vehicles, in which the height of a spring collar can be actively changed by the use of a hydraulic medium. A spring assembly of this type is intended especially for luxury class vehicles. For these types of vehicles, it must be expected that the spring collar will be adjusted relatively often as part of the process of regulating the level of the vehicle body.